diff --git a/src/Providers/ExtensionServiceProvider.php b/src/Providers/ExtensionServiceProvider.php
index d70ffa149f..2a32a74bc2 100644
--- a/src/Providers/ExtensionServiceProvider.php
+++ b/src/Providers/ExtensionServiceProvider.php
@@ -335,9 +335,12 @@ protected function registerAppExtensions($folder, $requiredClass)
             return;
         }
 
-        foreach ($this->app['files']->files($path) as $file) {
+        foreach ($this->app['files']->allFiles($path) as $file) {
+            $relativePathOfFolder = str_replace(app_path('/'), '', $file->getPath());
+            $namespace = str_replace('/', '\\', $relativePathOfFolder);
             $class = $file->getBasename('.php');
-            $fqcn = $this->app->getNamespace()."{$folder}\\{$class}";
+
+            $fqcn = $this->app->getNamespace()."{$namespace}\\{$class}";
             if (is_subclass_of($fqcn, $requiredClass)) {
                 $fqcn::register();
             }